Jacobson nerve is the eponymous name of the tympanic branch of the glossopharyngeal nerve (CN IX) and arises from the inferior ganglion of the glossopharyngeal nerve. It also carries preganglionic parasympathetic fibers, from the inferior salivary nucleus, which eventually enter the otic ganglion.
Jacobson nerve enters the tympanic cavity via the inferior tympanic canaliculus (Jacobson canal) and contributes to the tympanic plexus located on the cochlear promontory. The parasympathetic fibers leave the plexus as the lesser petrosal nerve.
The neuroendocrine cells related to this nerve give rise to glomus tympanicum tumors.
History and etymology
The nerve is named after Ludwig Levin Jacobson, (1783-1843) a Danish anatomist .